message.h 23.9 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
/*
 * Copyright (C) 1999  Internet Software Consortium.
 * 
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

18 19
#ifndef DNS_MESSAGE_H
#define DNS_MESSAGE_H 1
20 21 22 23 24

/***
 ***	Imports
 ***/

Michael Graff's avatar
Michael Graff committed
25
#include <isc/magic.h>
26
#include <isc/mem.h>
Michael Graff's avatar
Michael Graff committed
27
#include <isc/buffer.h>
28
#include <isc/bufferlist.h>
29 30 31 32 33

#include <dns/types.h>
#include <dns/result.h>
#include <dns/name.h>
#include <dns/rdataset.h>
34
#include <dns/rdatastruct.h>
Michael Graff's avatar
Michael Graff committed
35
#include <dns/compress.h>
36

37 38
#include <dst/dst.h>

39 40 41
/*
 * How this beast works:
 *
42
 * When a dns message is received in a buffer, dns_message_fromwire() is called
43 44 45 46 47 48 49 50
 * on the memory region.  Various items are checked including the format
 * of the message (if counts are right, if counts consume the entire sections,
 * and if sections consume the entire message) and known pseudo-RRs in the
 * additional data section are analyzed and removed.
 *
 * TSIG checking is also done at this layer, and any DNSSEC information should
 * also be performed at this time.
 *
51
 * If dns_message_fromwire() returns DNS_R_MOREDATA additional
52 53
 * message packets are required.  This implies an EDNS message.
 *
54
 * When going from structure to wire, dns_message_towire() will return
Michael Graff's avatar
typo  
Michael Graff committed
55
 * DNS_R_MOREDATA if there is more data left in the output buffer that
56 57
 * could not be rendered into the exisiting buffer.
 *
58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90
 *
 * Notes on using the gettemp*() and puttemp*() functions:
 *
 * These functions return items (names, rdatasets, etc) allocated from some
 * internal state of the dns_message_t.  These items must be put back into
 * the dns_message_t in one of two ways.  Assume a name was allocated via
 * dns_message_gettempname():
 *
 *	(1) insert it into a section, using dns_message_addname().
 *
 *	(2) return it to the message using dns_message_puttempname().
 *
 * The same applies to rdata, rdatasets, and rdatalists which were
 * allocated using this group of functions.
 *
 * Buffers allocated using isc_buffer_allocate() can be automatically freed
 * as well by giving the buffer to the message using dns_message_takebuffer().
 * Doing this will cause the buffer to be freed using isc_buffer_free()
 * when the section lists are cleared, such as in a reset or in a destroy.
 * Since the buffer itself exists until the message is destroyed, this sort
 * of code can be written:
 *
 *	buffer = isc_buffer_allocate(mctx, 512, ISC_BUFFERTYPE_BINARY);
 *	name = NULL;
 *	name = dns_message_gettempname(message, &name);
 *	dns_name_init(name, NULL);
 *	result = dns_name_fromtext(name, &source, dns_rootname, ISC_FALSE,
 *				   buffer);
 *	dns_message_takebuffer(message, &buffer);
 *
 *
 * TODO:
 *
91 92 93 94 95 96 97
 * XXX Needed:  ways to handle TSIG and DNSSEC, supply TSIG and DNSSEC
 * keys, set and retrieve EDNS information, add rdata to a section,
 * move rdata from one section to another, remove rdata, etc.
 */

ISC_LANG_BEGINDECLS

98 99 100 101 102
#define DNS_MESSAGEFLAG_QR		0x8000U
#define DNS_MESSAGEFLAG_AA		0x0400U
#define DNS_MESSAGEFLAG_TC		0x0200U
#define DNS_MESSAGEFLAG_RD		0x0100U
#define DNS_MESSAGEFLAG_RA		0x0080U
Bob Halley's avatar
Bob Halley committed
103 104
#define DNS_MESSAGEFLAG_AD		0x0020U
#define DNS_MESSAGEFLAG_CD		0x0010U
105

Bob Halley's avatar
Bob Halley committed
106
#define DNS_MESSAGE_REPLYPRESERVE	(DNS_MESSAGEFLAG_RD)
107

Bob Halley's avatar
Bob Halley committed
108 109 110
#define DNS_MESSAGE_HEADERLEN		12 /* 6 isc_uint16_t's */

#define DNS_MESSAGE_MAGIC		0x4d534740U	/* MSG@ */
Michael Graff's avatar
Michael Graff committed
111
#define DNS_MESSAGE_VALID(msg)		ISC_MAGIC_VALID(msg, DNS_MESSAGE_MAGIC)
Michael Graff's avatar
Michael Graff committed
112

Michael Graff's avatar
Michael Graff committed
113 114 115 116
/*
 * Ordering here matters.  DNS_SECTION_ANY must be the lowest and negative,
 * and DNS_SECTION_MAX must be one greater than the last used section.
 */
Michael Graff's avatar
Michael Graff committed
117
typedef int dns_section_t;
Michael Graff's avatar
Michael Graff committed
118
#define DNS_SECTION_ANY			(-1)
Michael Graff's avatar
Michael Graff committed
119 120 121 122
#define DNS_SECTION_QUESTION		0
#define DNS_SECTION_ANSWER		1
#define DNS_SECTION_AUTHORITY		2
#define DNS_SECTION_ADDITIONAL		3
123
#define DNS_SECTION_TSIG		4 /* pseudo-section */
124 125
#define DNS_SECTION_SIG0		5 /* pseudo-section */
#define DNS_SECTION_MAX			6
126 127 128 129 130 131 132

/*
 * Dynamic update named for these sections.
 */
#define DNS_SECTION_ZONE		DNS_SECTION_QUESTION
#define DNS_SECTION_PREREQUISITE	DNS_SECTION_ANSWER
#define DNS_SECTION_UPDATE		DNS_SECTION_AUTHORITY
Michael Graff's avatar
Michael Graff committed
133 134

/*
Michael Graff's avatar
Michael Graff committed
135
 * These tell the message library how the created dns_message_t will be used.
Michael Graff's avatar
Michael Graff committed
136
 */
Michael Graff's avatar
Michael Graff committed
137 138 139
#define DNS_MESSAGE_INTENTUNKNOWN	0 /* internal use only */
#define DNS_MESSAGE_INTENTPARSE		1 /* parsing messages */
#define DNS_MESSAGE_INTENTRENDER	2 /* rendering */
Michael Graff's avatar
Michael Graff committed
140

Michael Graff's avatar
Michael Graff committed
141 142
typedef struct dns_msgblock dns_msgblock_t;

Bob Halley's avatar
Bob Halley committed
143
struct dns_message {
Michael Graff's avatar
Michael Graff committed
144
	/* public from here down */
Michael Graff's avatar
Michael Graff committed
145
	unsigned int			magic;
146

147
	dns_messageid_t			id;
Michael Graff's avatar
Michael Graff committed
148 149 150
	unsigned int			flags;
	unsigned int			rcode;
	unsigned int			opcode;
Michael Graff's avatar
Michael Graff committed
151
	dns_rdataclass_t		rdclass;
Michael Graff's avatar
Michael Graff committed
152

153
	/* 4 real, 1 pseudo */
Michael Graff's avatar
Michael Graff committed
154
	unsigned int			counts[DNS_SECTION_MAX];
Michael Graff's avatar
Michael Graff committed
155 156

	/* private from here down */
Michael Graff's avatar
Michael Graff committed
157 158
	dns_namelist_t			sections[DNS_SECTION_MAX];
	dns_name_t		       *cursors[DNS_SECTION_MAX];
Bob Halley's avatar
Bob Halley committed
159
	dns_rdataset_t		       *opt;
160

Michael Graff's avatar
Michael Graff committed
161
	int				state;
Michael Graff's avatar
Michael Graff committed
162
	unsigned int			from_to_wire : 2;
163
	unsigned int			need_cctx_cleanup : 1;
Bob Halley's avatar
Bob Halley committed
164 165
	unsigned int			header_ok : 1;
	unsigned int			question_ok : 1;
166 167
	unsigned int			tcp_continuation : 1;
	unsigned int			verified_sig0 : 1;
168

169
	unsigned int			opt_reserved;
170
	unsigned int			reserved; /* reserved space (render) */
171

172
	isc_buffer_t		       *buffer;
Michael Graff's avatar
Michael Graff committed
173
	dns_compress_t			cctx;
174

Michael Graff's avatar
Michael Graff committed
175
	isc_mem_t		       *mctx;
176 177 178
	isc_mempool_t		       *namepool;
	isc_mempool_t		       *rdspool;

179
	isc_bufferlist_t		scratchpad;
180 181
	isc_bufferlist_t		cleanup;

Michael Graff's avatar
Michael Graff committed
182 183
	ISC_LIST(dns_msgblock_t)	rdatas;
	ISC_LIST(dns_msgblock_t)	rdatalists;
184 185 186

	ISC_LIST(dns_rdata_t)		freerdata;
	ISC_LIST(dns_rdatalist_t)	freerdatalist;
187 188 189 190 191

	dns_rcode_t			tsigstatus;
	dns_rcode_t			querytsigstatus;
	dns_rdata_any_tsig_t	       *tsig;
	dns_rdata_any_tsig_t	       *querytsig;
192
	dns_tsigkey_t		       *tsigkey;
193
	void			       *tsigctx;
194 195 196 197 198
	int				sigstart;

	dst_key_t		       *sig0key;
	dns_rcode_t			sig0status;
	isc_region_t		       *query;
Brian Wellington's avatar
Brian Wellington committed
199
	isc_region_t		       *saved;
Bob Halley's avatar
Bob Halley committed
200
};
201

Michael Graff's avatar
Michael Graff committed
202
dns_result_t
Bob Halley's avatar
Bob Halley committed
203 204 205
dns_message_create(isc_mem_t *mctx, unsigned int intent,
		   dns_message_t **msgp);
		   
206
/*
Michael Graff's avatar
Michael Graff committed
207
 * Create msg structure.
208
 *
Michael Graff's avatar
Michael Graff committed
209
 * This function will allocate some internal blocks of memory that are
Michael Graff's avatar
Michael Graff committed
210
 * expected to be needed for parsing or rendering nearly any type of message.
Michael Graff's avatar
Michael Graff committed
211 212 213
 *
 * Requires:
 *	'mctx' be a valid memory context.
214
 *
Michael Graff's avatar
Michael Graff committed
215
 *	'msgp' be non-null and '*msg' be NULL.
Michael Graff's avatar
Michael Graff committed
216
 *
Andreas Gustafsson's avatar
typo  
Andreas Gustafsson committed
217 218
 *	'intent' must be one of DNS_MESSAGE_INTENTPARSE or
 *	DNS_MESSAGE_INTENTRENDER.
Michael Graff's avatar
Michael Graff committed
219 220
 *
 * Ensures:
Michael Graff's avatar
Michael Graff committed
221
 *	The data in "*msg" is set to indicate an unused and empty msg
Michael Graff's avatar
Michael Graff committed
222 223 224
 *	structure.
 *
 * Returns:
225 226
 *	DNS_R_NOMEMORY		-- out of memory
 *	DNS_R_SUCCESS		-- success
227 228
 */

Michael Graff's avatar
Michael Graff committed
229
void
Bob Halley's avatar
Bob Halley committed
230
dns_message_reset(dns_message_t *msg, unsigned int intent);
Michael Graff's avatar
Michael Graff committed
231 232 233 234 235 236
/*
 * Reset a message structure to default state.  All internal lists are freed
 * or reset to a default state as well.  This is simply a more efficient
 * way to call dns_message_destroy() followed by dns_message_allocate(),
 * since it avoid many memory allocations.
 *
Michael Graff's avatar
Michael Graff committed
237 238 239
 * If any data loanouts (buffers, names, rdatas, etc) were requested,
 * the caller must no longer use them after this call.
 *
Bob Halley's avatar
Bob Halley committed
240 241
 * The intended next use of the message will be 'intent'.
 *
Michael Graff's avatar
Michael Graff committed
242 243 244
 * Requires:
 *
 *	'msg' be valid.
Bob Halley's avatar
Bob Halley committed
245 246
 *
 *	'intent' is DNS_MESSAGE_INTENTPARSE or DNS_MESSAGE_INTENTRENDER
Michael Graff's avatar
Michael Graff committed
247
 */
Michael Graff's avatar
Michael Graff committed
248

Michael Graff's avatar
Michael Graff committed
249
void
Michael Graff's avatar
Michael Graff committed
250
dns_message_destroy(dns_message_t **msgp);
Michael Graff's avatar
Michael Graff committed
251
/*
Michael Graff's avatar
Michael Graff committed
252 253 254 255
 * Destroy all state in the message.
 *
 * Requires:
 *
Michael Graff's avatar
Michael Graff committed
256
 *	'msgp' be valid.
Michael Graff's avatar
Michael Graff committed
257 258
 *
 * Ensures:
Michael Graff's avatar
Michael Graff committed
259
 *	'*msgp' == NULL
Michael Graff's avatar
Michael Graff committed
260 261
 */

Michael Graff's avatar
Michael Graff committed
262
dns_result_t
263 264
dns_message_parse(dns_message_t *msg, isc_buffer_t *source,
		  isc_boolean_t preserve_order);
Michael Graff's avatar
Michael Graff committed
265
/*
Michael Graff's avatar
Michael Graff committed
266 267 268 269 270 271 272
 * Parse raw wire data pointed to by "buffer" and bounded by "buflen" as a
 * DNS message.
 *
 * OPT records are detected and stored in the pseudo-section "opt".
 * TSIGs are detected and stored in the pseudo-section "tsig".  At detection
 * time, the TSIG is verified (XXX) and the message fails if the TSIG fails
 * to verify.
Michael Graff's avatar
Michael Graff committed
273
 *
274 275 276 277 278 279 280 281 282 283 284 285
 * If 'preserve_order' is true, or if the opcode of the message is UPDATE,
 * a separate dns_name_t object will be created for each RR in the message.
 * Each such dns_name_t will have a single rdataset containing the single RR,
 * and the order of the RRs in the message is preserved.
 * Otherwise, only one dns_name_t object will be created for each unique
 * owner name in the section, and each such dns_name_t will have a list
 * of rdatasets.  To access the names and their data, use 
 * dns_message_firstname() and dns_message_nextname(). 
 *
 * OPT and TSIG records are always handled specially, regardless of the
 * 'preserve_order' setting.
 *
Michael Graff's avatar
Michael Graff committed
286 287 288 289 290 291 292 293
 * If this is a multi-packet message (edns) and more data is required to
 * build the full message state, DNS_R_MOREDATA is returned.  In this case,
 * this function should be repeated with all input buffers until DNS_R_SUCCESS
 * (or an error) is returned.
 *
 * Requires:
 *	"msg" be valid.
 *
Michael Graff's avatar
Michael Graff committed
294
 *	"buffer" be a wire format binary buffer.
Michael Graff's avatar
Michael Graff committed
295 296 297 298
 *
 * Ensures:
 *	The buffer's data format is correct.
 *
Michael Graff's avatar
Michael Graff committed
299 300
 *	The buffer's contents verify as correct regarding header bits, buffer
 * 	and rdata sizes, etc.
Michael Graff's avatar
Michael Graff committed
301 302 303
 *
 * Returns:
 *	DNS_R_SUCCESS		-- all is well
Michael Graff's avatar
Michael Graff committed
304
 *	DNS_R_NOMEMORY		-- no memory
Michael Graff's avatar
Michael Graff committed
305
 *	DNS_R_MOREDATA		-- more packets needed for complete message
Michael Graff's avatar
Michael Graff committed
306 307
 *	DNS_R_???		-- bad signature (XXXMLG need more of these)
 *	Many other errors possible XXXMLG
Michael Graff's avatar
Michael Graff committed
308 309
 */

Michael Graff's avatar
Michael Graff committed
310 311
dns_result_t
dns_message_renderbegin(dns_message_t *msg, isc_buffer_t *buffer);
Michael Graff's avatar
Michael Graff committed
312
/*
Michael Graff's avatar
Michael Graff committed
313 314
 * Begin rendering on a message.  Only one call can be made to this function
 * per message.
Michael Graff's avatar
Michael Graff committed
315
 *
Michael Graff's avatar
Michael Graff committed
316 317 318
 * The buffer is "owned" buy the message library until dns_message_renderend()
 * is called.
 *
Michael Graff's avatar
Michael Graff committed
319
 * Requires:
Michael Graff's avatar
Michael Graff committed
320 321
 *
 *	'msg' be valid.
322
 *
Michael Graff's avatar
Michael Graff committed
323 324 325 326 327
 *	buffer is a valid binary buffer.
 *
 * Side Effects:
 *
 *	The buffer is cleared before it is used.
328
 *
Michael Graff's avatar
Michael Graff committed
329 330 331 332
 * Returns:
 *	DNS_R_SUCCESS		-- all is well
 *	DNS_R_NOSPACE		-- output buffer is too small
 *	Anything that dns_compress_init() can return.
Michael Graff's avatar
Michael Graff committed
333 334 335
 */

dns_result_t
336 337 338 339 340
dns_message_renderchangebuffer(dns_message_t *msg, isc_buffer_t *buffer);
/*
 * Reset the buffer.  This can be used after growing the old buffer
 * on a DNS_R_NOSPACE return from most of the render functions.
 *
Michael Graff's avatar
Michael Graff committed
341 342 343 344
 * On successful completion, the old buffer is no longer used by the
 * library.  The new buffer is owned by the library until
 * dns_message_renderend() is called.
 *
345 346 347 348 349 350 351 352 353
 * Requires:
 *
 *	'msg' be valid.
 *
 *	dns_message_renderbegin() was called.
 *
 *	buffer != NULL.
 *
 * Returns:
354 355
 *	DNS_R_NOSPACE		-- new buffer is too small
 *	DNS_R_SUCCESS		-- all is well.
356 357 358 359
 */

dns_result_t
dns_message_renderreserve(dns_message_t *msg, unsigned int space);
Michael Graff's avatar
Michael Graff committed
360
/*
Michael Graff's avatar
Michael Graff committed
361 362 363
 * XXXMLG should use size_t rather than unsigned int once the buffer
 * API is cleaned up
 *
Michael Graff's avatar
Michael Graff committed
364 365 366 367 368
 * Reserve "space" bytes in the given buffer.
 *
 * Requires:
 *
 *	'msg' be valid.
Michael Graff's avatar
Michael Graff committed
369
 *
370 371
 *	dns_message_renderbegin() was called.
 *
Michael Graff's avatar
Michael Graff committed
372
 * Returns:
Michael Graff's avatar
Michael Graff committed
373 374
 *	DNS_R_SUCCESS		-- all is well.
 *	DNS_R_NOSPACE		-- not enough free space in the buffer.
Michael Graff's avatar
Michael Graff committed
375 376
 */

377
void
Michael Graff's avatar
Michael Graff committed
378 379
dns_message_renderrelease(dns_message_t *msg, unsigned int space);
/*
Michael Graff's avatar
Michael Graff committed
380 381 382
 * XXXMLG should use size_t rather than unsigned int once the buffer
 * API is cleaned up
 *
Michael Graff's avatar
Michael Graff committed
383 384 385 386 387 388
 * Release "space" bytes in the given buffer that was previously reserved.
 *
 * Requires:
 *
 *	'msg' be valid.
 *
389 390
 *	'space' is less than or equal to the total amount of space reserved
 *	via prior calls to dns_message_renderreserve().
391
 *
392
 *	dns_message_renderbegin() was called.
Michael Graff's avatar
Michael Graff committed
393 394
 */

Michael Graff's avatar
Michael Graff committed
395
dns_result_t
396
dns_message_rendersection(dns_message_t *msg, dns_section_t section,
Michael Graff's avatar
Michael Graff committed
397
			  unsigned int priority, unsigned int options);
Michael Graff's avatar
Michael Graff committed
398
/*
Michael Graff's avatar
Michael Graff committed
399 400
 * Render all names, rdatalists, etc from the given section at the
 * specified priority or higher.
Michael Graff's avatar
Michael Graff committed
401 402
 *
 * Requires:
Michael Graff's avatar
Michael Graff committed
403 404 405
 *	'msg' be valid.
 *
 *	'section' be a valid section.
Michael Graff's avatar
Michael Graff committed
406
 *
407 408
 *	dns_message_renderbegin() was called.
 *
Michael Graff's avatar
Michael Graff committed
409
 * Returns:
Michael Graff's avatar
Michael Graff committed
410 411 412 413 414 415
 *	DNS_R_SUCCESS		-- all records were written, and there are
 *				   no more records for this section.
 *	DNS_R_NOSPACE		-- Not enough room in the buffer to write
 *				   all records requested.
 *	DNS_R_MOREDATA		-- All requested records written, and there
 *				   are records remaining for this section.
Michael Graff's avatar
Michael Graff committed
416 417
 */

418 419 420 421 422 423 424 425 426 427 428 429 430 431 432
void
dns_message_renderheader(dns_message_t *msg, isc_buffer_t *target);
/*
 * Render the message header.  This is implicitly called by
 * dns_message_renderend().
 *
 * Requires:
 *
 *	'msg' be a valid message.
 *
 *	dns_message_renderbegin() was called.
 *
 *	'target' is a valid buffer with enough space to hold a message header
 */

Michael Graff's avatar
Michael Graff committed
433
dns_result_t
434
dns_message_renderend(dns_message_t *msg);
Michael Graff's avatar
Michael Graff committed
435
/*
Michael Graff's avatar
Michael Graff committed
436 437 438 439 440 441 442 443
 * Finish rendering to the buffer.  Note that more data can be in the
 * 'msg' structure.  Destroying the structure will free this, or in a multi-
 * part EDNS1 message this data can be rendered to another buffer later.
 *
 * Requires:
 *
 *	'msg' be a valid message.
 *
444 445
 *	dns_message_renderbegin() was called.
 *
Michael Graff's avatar
Michael Graff committed
446 447 448 449 450 451 452 453 454 455
 * Returns:
 *	DNS_R_SUCCESS		-- all is well.
 */
		      

dns_result_t
dns_message_firstname(dns_message_t *msg, dns_section_t section);
/*
 * Set internal per-section name pointer to the beginning of the section.
 *
Michael Graff's avatar
Michael Graff committed
456
 * The functions dns_message_firstname() and dns_message_nextname() may
457
 * be used for iterating over the owner names in a section. 
Michael Graff's avatar
Michael Graff committed
458
 *
Michael Graff's avatar
Michael Graff committed
459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481
 * Requires:
 *
 *   	'msg' be valid.
 *
 *	'section' be a valid section.
 *
 * Returns:
 *	DNS_R_SUCCESS		-- All is well.
 *	DNS_R_NOMORE		-- No names on given section.
 */

dns_result_t
dns_message_nextname(dns_message_t *msg, dns_section_t section);
/*
 * Sets the internal per-section name pointer to point to the next name
 * in that section.
 *
 * Requires:
 *
 *   	'msg' be valid.
 *
 *	'section' be a valid section.
 *
Michael Graff's avatar
Michael Graff committed
482 483 484
 *	dns_message_firstname() must have been called on this section,
 *	and the result was DNS_R_SUCCESS.
 *
Michael Graff's avatar
Michael Graff committed
485 486 487 488 489
 * Returns:
 *	DNS_R_SUCCESS		-- All is well.
 *	DNS_R_NOMORE		-- No names in given section.
 */

Michael Graff's avatar
Michael Graff committed
490
void
Michael Graff's avatar
Michael Graff committed
491 492 493 494 495 496
dns_message_currentname(dns_message_t *msg, dns_section_t section,
			dns_name_t **name);
/*
 * Sets 'name' to point to the name where the per-section internal name
 * pointer is currently set.
 *
Michael Graff's avatar
Michael Graff committed
497 498 499
 * This function returns the name in the database, so any data associated
 * with it (via the name's "list" member) contains the actual rdatasets.
 *
Michael Graff's avatar
Michael Graff committed
500 501 502 503 504 505 506 507
 * Requires:
 *
 *	'msg' be valid.
 *
 *	'name' be non-NULL, and *name be NULL.
 *
 *	'section' be a valid section.
 *
Michael Graff's avatar
Michael Graff committed
508 509 510
 *	dns_message_firstname() must have been called on this section,
 *	and the result of it and any dns_message_nextname() calls was
 *	DNS_R_SUCCESS.
Michael Graff's avatar
Michael Graff committed
511 512
 */

Michael Graff's avatar
Michael Graff committed
513 514 515
dns_result_t
dns_message_findname(dns_message_t *msg, dns_section_t section,
		     dns_name_t *target, dns_rdatatype_t type,
Bob Halley's avatar
Bob Halley committed
516 517
		     dns_rdatatype_t covers, dns_name_t **foundname,
		     dns_rdataset_t **rdataset);
Michael Graff's avatar
Michael Graff committed
518
/*
Michael Graff's avatar
Michael Graff committed
519 520
 * Search for a name in the specified section.  If it is found, *name is
 * set to point to the name, and *rdataset is set to point to the found
Bob Halley's avatar
Bob Halley committed
521
 * rdataset (if type is specified as other than dns_rdatatype_any).
Michael Graff's avatar
Michael Graff committed
522 523 524 525 526 527
 *
 * Requires:
 *	'msg' be valid.
 *
 *	'section' be a valid section.
 *
Michael Graff's avatar
Michael Graff committed
528 529
 *	If a pointer to the name is desired, 'foundname' should be non-NULL.
 *	If it is non-NULL, '*foundname' MUST be NULL.
Michael Graff's avatar
Michael Graff committed
530 531 532
 *
 *	If a type other than dns_datatype_any is searched for, 'rdataset'
 *	may be non-NULL, '*rdataset' be NULL, and will point at the found
Michael Graff's avatar
Michael Graff committed
533
 *	rdataset.  If the type is dns_datatype_any, 'rdataset' must be NULL.
Michael Graff's avatar
Michael Graff committed
534 535 536 537 538 539 540 541 542 543
 *
 *	'target' be a valid name.
 *
 *	'type' be a valid type.
 *
 * Returns:
 *	DNS_R_SUCCESS		-- all is well.
 *	DNS_R_NXDOMAIN		-- name does not exist in that section.
 *	DNS_R_NXRDATASET	-- The name does exist, but the desired
 *				   type does not.
Michael Graff's avatar
Michael Graff committed
544 545
 */

546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562
dns_result_t
dns_message_findtype(dns_name_t *name, dns_rdatatype_t type,
		     dns_rdatatype_t covers, dns_rdataset_t **rdataset);
/*
 * Search the name for the specified type.  If it is found, *rdataset is
 * filled in with a pointer to that rdataset.
 *
 * Requires:
 *	if '**rdataset' is non-NULL, *rdataset needs to be NULL.
 *
 *	'type' be a valid type, and NOT dns_rdatatype_any.
 *
 * Returns:
 *	DNS_R_SUCCESS		-- all is well.
 *	DNS_R_NOTFOUND		-- the desired type does not exist.
 */

Michael Graff's avatar
Michael Graff committed
563 564 565 566
void
dns_message_movename(dns_message_t *msg, dns_name_t *name,
		     dns_section_t fromsection,
		     dns_section_t tosection);
Michael Graff's avatar
Michael Graff committed
567 568
/*
 * Move a name from one section to another.
Michael Graff's avatar
Michael Graff committed
569 570 571 572 573
 *
 * Requires:
 *
 *	'msg' be valid.
 *
Michael Graff's avatar
Michael Graff committed
574
 *	'name' must be a name already in 'fromsection'.
Michael Graff's avatar
Michael Graff committed
575 576 577
 *
 *	'fromsection' must be a valid section.
 *
Michael Graff's avatar
Michael Graff committed
578
 *	'tosection' must be a valid section.
Michael Graff's avatar
Michael Graff committed
579 580
 */

Michael Graff's avatar
Michael Graff committed
581 582 583
void
dns_message_addname(dns_message_t *msg, dns_name_t *name,
		    dns_section_t section);
Michael Graff's avatar
Michael Graff committed
584 585 586
/*
 * Adds the name to the given section.
 *
Michael Graff's avatar
Michael Graff committed
587 588
 * It is the caller's responsibility to enforce any unique name requirements
 * in a section.
Michael Graff's avatar
Michael Graff committed
589 590 591 592 593 594 595 596
 *
 * Requires:
 *
 *	'msg' be valid, and be a renderable message.
 *
 *	'name' be a valid name.
 *
 *	'section' be a named section.
Michael Graff's avatar
Michael Graff committed
597
 */
598

599 600 601 602 603 604 605 606 607 608 609 610
/*
 * LOANOUT FUNCTIONS
 *
 * Each of these functions loan a particular type of data to the caller.
 * The storage for these will vanish when the message is destroyed or
 * reset, and must NOT be used after these operations.
 */

dns_result_t
dns_message_gettempname(dns_message_t *msg, dns_name_t **item);
/*
 * Return a name that can be used for any temporary purpose, including
611 612 613
 * inserting into the message's linked lists.  The name must be returned
 * to the message code using dns_message_puttempname() or inserted into
 * one of the message's sections before the message is destroyed.
614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737
 *
 * It is the caller's responsibility to initialize this name.
 *
 * Requires:
 *	msg be a valid message
 *
 *	item != NULL && *item == NULL
 *
 * Returns:
 *	DNS_R_SUCCESS		-- All is well.
 *	DNS_R_NOMEMORY		-- No item can be allocated.
 */

dns_result_t
dns_message_gettemprdata(dns_message_t *msg, dns_rdata_t **item);
/*
 * Return a rdata that can be used for any temporary purpose, including
 * inserting into the message's linked lists.  The storage associated with
 * this rdata will be destroyed when the message is destroyed or reset.
 *
 * Requires:
 *	msg be a valid message
 *
 *	item != NULL && *item == NULL
 *
 * Returns:
 *	DNS_R_SUCCESS		-- All is well.
 *	DNS_R_NOMEMORY		-- No item can be allocated.
 */

dns_result_t
dns_message_gettemprdataset(dns_message_t *msg, dns_rdataset_t **item);
/*
 * Return a rdataset that can be used for any temporary purpose, including
 * inserting into the message's linked lists.  The storage associated with
 * this rdataset will be destroyed when the message is destroyed or reset.
 *
 * Requires:
 *	msg be a valid message
 *
 *	item != NULL && *item == NULL
 *
 * Returns:
 *	DNS_R_SUCCESS		-- All is well.
 *	DNS_R_NOMEMORY		-- No item can be allocated.
 */

dns_result_t
dns_message_gettemprdatalist(dns_message_t *msg, dns_rdatalist_t **item);
/*
 * Return a rdatalist that can be used for any temporary purpose, including
 * inserting into the message's linked lists.  The storage associated with
 * this rdatalist will be destroyed when the message is destroyed or reset.
 *
 * Requires:
 *	msg be a valid message
 *
 *	item != NULL && *item == NULL
 *
 * Returns:
 *	DNS_R_SUCCESS		-- All is well.
 *	DNS_R_NOMEMORY		-- No item can be allocated.
 */

void
dns_message_puttempname(dns_message_t *msg, dns_name_t **item);
/*
 * Return a borrowed name to the message's name free list.
 *
 * Requires:
 *	msg be a valid message
 *
 *	item != NULL && *item point to a name returned by
 *	dns_message_gettempname()
 *
 * Ensures:
 *	*item == NULL
 */

void
dns_message_puttemprdata(dns_message_t *msg, dns_rdata_t **item);
/*
 * Return a borrowed rdata to the message's rdata free list.
 *
 * Requires:
 *	msg be a valid message
 *
 *	item != NULL && *item point to a rdata returned by
 *	dns_message_gettemprdata()
 *
 * Ensures:
 *	*item == NULL
 */

void
dns_message_puttemprdataset(dns_message_t *msg, dns_rdataset_t **item);
/*
 * Return a borrowed rdataset to the message's rdataset free list.
 *
 * Requires:
 *	msg be a valid message
 *
 *	item != NULL && *item point to a rdataset returned by
 *	dns_message_gettemprdataset()
 *
 * Ensures:
 *	*item == NULL
 */

void
dns_message_puttemprdatalist(dns_message_t *msg, dns_rdatalist_t **item);
/*
 * Return a borrowed rdatalist to the message's rdatalist free list.
 *
 * Requires:
 *	msg be a valid message
 *
 *	item != NULL && *item point to a rdatalist returned by
 *	dns_message_gettemprdatalist()
 *
 * Ensures:
 *	*item == NULL
 */

Michael Graff's avatar
Michael Graff committed
738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761
dns_result_t
dns_message_peekheader(isc_buffer_t *source, dns_messageid_t *idp,
		       unsigned int *flagsp);
/*
 * Assume the remaining region of "source" is a DNS message.  Peek into
 * it and fill in "*idp" with the message id, and "*flagsp" with the flags.
 *
 * Requires:
 *
 *	source != NULL
 *
 * Ensures:
 *
 *	if (idp != NULL) *idp == message id.
 *
 *	if (flagsp != NULL) *flagsp == message flags.
 *
 * Returns:
 *
 *	DNS_R_SUCCESS		-- all is well.
 *
 *	DNS_R_UNEXPECTEDEND	-- buffer doesn't contain enough for a header.
 */

Bob Halley's avatar
Bob Halley committed
762 763 764 765 766 767 768
dns_result_t
dns_message_reply(dns_message_t *msg, isc_boolean_t want_question_section);
/*
 * Start formatting a reply to the query in 'msg'.
 *
 * Requires:
 *
Bob Halley's avatar
EDNS0  
Bob Halley committed
769
 *	'msg' is a valid message with parsing intent, and contains a query.
Bob Halley's avatar
Bob Halley committed
770 771 772 773
 * 
 * Ensures:
 *
 *	The message will have a rendering intent.  If 'want_question_section'
774 775 776 777 778
 *	is true, the message opcode is query or notify, and the question
 *	section is present and properly formatted, then the question section
 *	will be included in the reply.  All other sections will be cleared.
 *	The QR flag will be set, the RD flag will be preserved, and all other
 *	flags will be cleared.
Bob Halley's avatar
Bob Halley committed
779 780 781 782 783
 *
 * Returns:
 *
 *	DNS_R_SUCCESS		-- all is well.
 *
Bob Halley's avatar
Bob Halley committed
784 785 786 787 788 789 790
 *	DNS_R_FORMERR		-- the header or question section of the
 *				   message is invalid, replying is impossible.
 *				   If DNS_R_FORMERR is returned when
 *				   want_question_section is ISC_FALSE, then
 *				   it's the header section that's bad;
 *				   otherwise either of the header or question
 *				   sections may be bad.
Bob Halley's avatar
Bob Halley committed
791 792
 */

Bob Halley's avatar
EDNS0  
Bob Halley committed
793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831
dns_rdataset_t *
dns_message_getopt(dns_message_t *msg);
/*
 * Get the OPT record for 'msg'.
 *
 * Requires:
 *
 *	'msg' is a valid message.
 *
 * Returns:
 *
 *	The OPT rdataset of 'msg', or NULL if there isn't one.
 */

dns_result_t
dns_message_setopt(dns_message_t *msg, dns_rdataset_t *opt);
/*
 * Set the OPT record for 'msg'.
 *
 * Requires:
 *
 *	'msg' is a valid message with rendering intent,
 *	dns_message_renderbegin() has been called, and no sections have been
 *	rendered.
 *
 *	'opt' is a valid OPT record.
 *
 * Ensures:
 *
 *	The OPT record will be rendered when dns_message_renderend() is
 *	called.
 *
 * Returns:
 *
 *	DNS_R_SUCCESS		-- all is well.
 *
 *	DNS_R_NOSPACE		-- there is no space for the OPT record.
 */

832 833 834 835 836 837 838 839 840 841 842 843 844 845 846
void
dns_message_takebuffer(dns_message_t *msg, isc_buffer_t **buffer);
/*
 * Give the *buffer to the message code to clean up when it is no
 * longer needed.  This is usually when the message is reset or
 * destroyed.
 *
 * Requires:
 *
 *	msg be a valid message.
 *
 *	buffer != NULL && *buffer is a valid isc_buffer_t, which was
 *	dynamincally allocated via isc_buffer_allocate().
 */

Brian Wellington's avatar
Brian Wellington committed
847
isc_result_t
848
dns_message_signer(dns_message_t *msg, dns_name_t *signer);
Brian Wellington's avatar
Brian Wellington committed
849
/*
850
 * If this message was signed, return the identity of the signer.
Brian Wellington's avatar
Brian Wellington committed
851 852
 * Unless ISC_R_NOTFOUND is returned, signer will reflect the name of the
 * key that signed the message.
Brian Wellington's avatar
Brian Wellington committed
853 854 855
 *
 * Requires:
 *
856 857
 *	msg is a valid parsed message.
 *	signer is a valid name
Brian Wellington's avatar
Brian Wellington committed
858 859 860 861 862 863
 *
 * Returns:
 *
 *	ISC_R_SUCCESS		- the message was signed, and *signer
 *				  contains the signing identity
 *
864
 *	ISC_R_NOTFOUND		- no TSIG or SIG(0) record is present in the
Brian Wellington's avatar
Brian Wellington committed
865 866
 *				  message
 *
867 868 869 870 871 872 873 874 875 876
 *	DNS_R_TSIGVERIFYFAILURE	- the message was signed by a TSIG, but the
 *				  signature failed to verify
 *
 *	DNS_R_TSIGERRORSET	- the message was signed by a TSIG and
 *				  verified, but the query was rejected by
 *				  the server
 *
 *	DNS_R_NOIDENTITY	- the message was signed by a TSIG and
 *				  verified, but the key has no identity since
 *				  it was generated by an unsigned TKEY process
Brian Wellington's avatar
Brian Wellington committed
877
 *
878 879
 *	DNS_R_SIGINVALID	- the message was signed by a SIG(0), but
 *				  the signature failed to verify
Brian Wellington's avatar
Brian Wellington committed
880
 *
881 882
 *	DNS_R_SIGNOTVERIFIEDYET	- the message was signed by a SIG(0), but
 *				  the signature has not been verified yet
Brian Wellington's avatar
Brian Wellington committed
883 884
 */

885 886
ISC_LANG_ENDDECLS

887
#endif	/* DNS_MESSAGE_H */